Deaerator for carbonating systems



Aug. 12, 1941. R. N. BOSTOCK 2,252,313 namnuon FOR CARBONATING SYSTEMS Filed March 31, 1939 .fl 1 Jug 4 w l I mm k g s \D iL v r a w 7] INVENTOR 1 5 ATTORNEYJ Patented Aug. 12, 1941 DEAERATOR. FOR QARBONATING I SYSTEMS Raymond N. Bostock, Upper Montclair, N. J.

l Application March 31, 1939, Serial No. 265,087

ll Claim.

My invention relates to the deaerating of water and will be particularly useful in the carbonated beverage industry.

It is the primary object of ,my invention to provide a novel method and means for the deaeration of water in which the water may be deaerated to a commercially practical extent with comparatively inexpensive apparatus.

It is a further object of my invention to provide a method and means for the' deaeration of water by use of a neutral or desirable gas to reducethe partial pressure of air in the deaerator.

Another object of my invention is to-provide a process by means of deaerating water in the carbonating system involving the utilization of waste gas from the carbonator to assist in the deaeration.

In the carbonated beverage industry it has been customary to carbonate water by mixing the water with carbon dioxide gas underpressure. It is desirable to produce a carbonated water as free of air as possible; first, because the presence of air causes a rapid ebullition of gas after a bottle is opened and therefore causes the carbonated beverage to go fiat quickly; secondly, because in the operation of filling bottles with the carbonated beverage, gas tends to boil or: with the result that the" bottles are not completely filled, or are short." This enforces slower operating speeds as it is necessary to release the pressure on the bottle more slowly in order to prevent violent ebullition of gas. It can be seen, therefore, that it is very desirable to free the water of air so far as possible both from the standpoint of the quality of the beverage and for economy in operation.

Many deaerators have been designed for the purposes above set forth. All operate, in general, on the principle of applying a vacuum to water in a closed vesselthereby decreasing the solubility of the air and removing it by means of a vacuum pump or steam ejector. So far as I am aware, however, deaerators designed for the carbonated beverage industry have proved to be impractical from a commercial point of view because of the expense involved in producing a high enough vacuum in present systems. In present systems it is necessary to produce a vacuum of approximately 29.8 inches, or within flinch of a mercially justifiable cost. As a result there are very few manufacturers of beverages who attempt apparatus and. method which I will now describe.

The single figure of the drawing illustrates diagrammatically in preferred form a carbonating system embodying a novel arrangement of parts and in which my improved method can be carried out.

The system in general comprises carbonator A, cooler B and deaerator C. The connections are such that the system can be operated without using the cooler if desired.

The carbonator A may be of any knownv type. Carbon dioxide gas is introduced by means of the pipe 1. Water to the carbonator is supplied by means of pipe 2 which leads from the cooler or deaerator, as will. be hereinafter explained. The water and carbon dioxide are thoroughly mixed in the carbonator at a pressure anywhere from 30 to pounds per square inch and after carbonation has been effected the water is led from the carbonator to point of use by means of the pipe 3.

Commercial carbon dioxide gas contains 99.7% CO2 and about 1 6% air. If this air is not eliminated in the carbonator it will build up and accumulate until a dangerously high percentage of air will exist in the carbonator. For this reason, most carbonators are equipped with a. so-called snift or small blow-oil connection which allows a small amount of gas within the carbonator to into the cooler and thence by means of pipe 6 to the deaerator. If desired, however, the cooler may be by-passed and the gas led from pipe 4 to pipe I, thence through pipe 6 to the deaerator.

I will first describe the system as it is operated with the cooler in use. To operate the system in this way the valve in the gas line 1 is closed, and

the valve 9 in the line 5 and the valves I0 and II in line 6 are opened. Gas flows from the carbonator through lines 4 and 5, through the pressure control valve l2 to, the distributor pipe I 3 located below the water level in the bottom of the cooler. The cooler comprises a gas-tight enclosure within which is located the'coolin apparatus I5. A cooling medium is circulated through the cooler by means of inlet pipe l6 and outlet pipe l1. Water from the deaerator enters the cooler through the pipe l6 and distributor [9 from which it is sprayed over the cooling apparatus i and collects in the bottom of the cooler B proper. Snift gas from the carbonator A leaves the distributor l3 at various points and bubbles up through the water collected in the bottom of the cooler. The pressure control valve I2 is set to maintain 2 to 8 ounces per square inch pressure'within the cooler. A float 20, or water level control device, is located within the cooler and operates the electrical control mechanism 33 for a purpose to be hereinafter explained.

The cooled water is pumped from the cooler B to the carbonator A by means of the pump 2| and is carbonated in the carbonator as before explained.

After passing through the cooler the snift gas is led by pipe 6 to the distributor 22 in the deaerator C. In addition to the manually operated valve ll there is an electrical'control valve 23 in,

line 6 to control the flow of gas from the cooler to the deaerator.

The deaerator proper consists of an airtight casing 24 having baffles 25 in the upper part thereof- Water is admitted to the top of the deaerator through the pipe 25 controlled by manually operated valve 26 and electrically operated valve 21. The water entering through pipe 25 comes from the usual source of supply and may be filtered, but whatever the source of supply it will generally be found that this water contains much air both in the form of dissolved air and occluded air and it is the purpose of the deaerator to rid the water of this air.

Vacuum pump 28 is connected to the upper part ofthe deaerator by means of the pipe 29. In my system it is not necessary that this be a pump capable of producing the vacuum of the order heretofore, mentioned (29.8 inches) but may be a small pump capable of producing 27 to 28 inches vacuum. Such pumps are available at reasonable cost and can be used with perfectly satisfactory resultsin my improved system.

The deaerated water is pumped from the deaerator 24 by means of th pump 29 connected to the-deaerator by the pipe 30. Back pressure valve 3|, located in the line I8, is arranged to close in case of pressure failure. Another electrically controlled valve 32 is also located in this line and is controlled by the electrical control mechanism 33. There is a by-pass 34 to by-pass the water around the cooler when the cooler is not in use. When the cooler is being used, manually controlled valves 35 and 31 are open and manually controlled valve 3615 closed.

Valves 23, 21 and 32 are electrically operated under. control mechanism 33 which in turn is operated by the float 20. When the water level in the cooler B reaches a certain predetermined height the float operates the control mechanism to close thethree valves mentioned; i. e., 23, 21

and 32, thus stopping operation of the deaerator until the water level in the cooler B falls below ever, even better results can be obtained.

When the system is in operation with the.

cooler the deaerated water is pumped from the deaerator by means of the pump 29 through the line It to the distributor I! as hereinbefore explained.

As above pointed out, it is not necessary to use the cooler in order to secure satisfactory deaeration. In some plants it may be desirable to dispense with the cooler entirely and in other cases, even when there isa cooler, it may be desirable on occasion to operate without it. I have, therefore, provided the by-pass above referred to by means of which the cooler can be cut out of the system.

-In order to by-pass the cooler .it is necessary only to close the valves 9, I0, 35 and 31 and to open the valves '8 and 36. This will permit the water to flow directly from the deaerator to the carbonator and the gas from the carbonator to flow directly to the deaerator. In other respects the operation of the system will be the same.

Deaeration of the water is effected in the following manner: It is the law of solubility of gases that at any given temperature the solubilthe air instead of being 3.inches will be only .3

inch and the solubility of th air will, therefore, be M of the solubility at atmospheric pressure, or practically the same as the solubility in the extremely high vacuum systems.

My improved system is based on the foregoing law of solubility of gases. The snift gas from the carbonator which is ordinarily wasted as above pointed out is generally 99.0 to 99.2% pure carbon dioxide. Instead of wasting this gas, in

my improved system it is introduced into the bottom of the deaerator through the distributor 22 and bubbles up through the water and passes upward across the baffles, thus producing an agitation in the water much akin to the agitation caused by boiling which may be found in the high vacuum systems. At the same time by the introduction of the snift gas the partial pressure of the air in the deaerator is decreased as it is diluted at least ten to one with carbon dioxide and there is produced in the deaerator a partial pressure of air which gives practical'deaeration at 27 inches vacuum.

The foregoing method of operation has been described without taking into account the cooler. The method of operation thus described is perfectly practical in order to secure a very high degree of deaeration. By using a cooler, how- When the cooler is used there is in general a counter flow of gas and water as follows: The snift gas leaves the carbonator, enters the cooler and from water, on the other hand, enters the deaerator,

The

flows to the cooler through thepipe I 8, leaves bonator.

In the cooler the gas from the distributor l3 bubbles upward through the water and. the water in the cooler is surrounded by an atmosphere of carbon dioxide at a pressure of 2 to 10 ounces per square inch. The water from the deaerator enters the cooler in deaeratedcondition, and, in the cooler, comes in contact with an atmosphere of carbon dioxide 97 to 98% pure. In trickling down over the cooler mechanism IS the water is cooled to about 32-33 F. and at the same time, absorbs a certain amount of carbon dioxide becaus of the reduced temperature or the water. I found in practice that in my improved system water will enter the carbonator at about 33 F. with initial carbonation of 1 volumes. In the carbonator the gas in contar t with carbon dioxide is under pressure and receives its final carbonation.

l The gas entering the carbonator is approximately 99.7% pure and the greater proportion of it is absorbed by the water. The small proportion of the gas leaving the carbonatorin the form of shift gas is about 99% pure as it enters the cooler and in the cooler a large'proportion is again absorbed so that the gas leaving the cooler is about 97% pure and it is this gas which is finally introduced into the deaerator.

It will be seen, therefore, that the gas which leaves the deaerator is of much lower purity thanthe gas heretofore wasted and this results in a considerable economy 01 gas aswell as in much improved quality of the product with respect to deaeration.

the cooler through the line 2 and enters the car- Throughout this specification, and in the claims I have referred to the gas leaving the carbonator as waste gas, as it is this gas which has heretofore been"wasted.. It will be understood, however, in my process the gas from the carbonator is not, strictly speaking, waste gas as it is put to very good use as above described.

Because of the factthat in my improved systom the gas is not wasted it is possible 'from the standpoint of economy to permit a very much greater flow of shift gas than in present systems. This maintains a very much higher purity of gas in the carbonator, which in turn. gives finished carbonated water with less air than would otherwise be the case.

It will also be understood that if desired, carbon dioxide from a source other than the carbonator could be used in the cooler or deaerator with equally effective results, although the results from the standpoint of economy would probably not b so good.

I claim:

In a carbonating system, a carbonator having a snift outlet, a cooler and a deaerating chamber having an inlet for water to be carbonated, means for reducing the pressure in the deareating chamber below atmospheric including a pump which alone is incapable of producing the required deaeration of the water, means for circulating water from the deaerating chamber through the cooler to the carbonator, and means for circulating waste carbon dioxide from the snift ofthe carbonator through the cooler to the deaerating chamber whereby there is a counterflow of gas and water in-the system.

RAYMOND N. BOSTOCK. 

